Recently, the number of users playing a massively multiplayer online role-playing game (MMORPG) has been steadily increasing. Also, as mobile devices such as smartphones and tablet personal computers are implemented using advanced technologies for greater computing power, the users are now able to play MMORPGs on the mobile devices as well as other non-portable computing devices such as desktop computers. Since the mobile devices with such computing power enables sophisticated 3-dimensional graphic rendering, the graphics quality of the MMORPGs provided on mobile devices is now comparable to that for non-portable computing devices.
MMORPGs may be provided in the form of so-called “Play4Free (P4F)” where the users are allowed to use basic features of the games for free while they need to purchase virtual items for more advanced features. In such type of games, it is important to implement a mechanism that encourages the users to continuously play the games so that the users can be exposed to more chances for purchasing the virtual items. In particular, in order to encourage as many users as possible to regularly purchase items, it may be necessary to adjust the balance of various factors in the games so as to motivate the users to purchase the items through cooperation or competition among the users.
However, it is difficult to motivate the users having various lifestyles to continuously attend the same P4F MMORPG. For example, cooperative playing of a game may not be made between a first user, who can play the game for an ample amount of time (e.g., a student regularly playing the game for several hours a day), and a second user, who can play the game only for a limited amount of time (e.g., a regular worker intermittently playing the game at night times). In this case, the first user can constitute a volume of the game users, whereas the second user can constitute important consumers who purchase charged-for items. In light of these circumstances, MMORPGs may be configured to provide different types of games for users having different characteristics such as different levels of skills and/or different lifestyles. For examples, for novice users who tend to often switch from one game title to another, a game service provider tends to provide a web-based simple 2-dimensional user interface (UI) which can be implemented at low costs. On the other hand, for intermediate or high level users who tend to pay for advanced features, the game service provider tends to provide a full-fledged 3-dimensional UI which can be implemented at high costs.
As described above, the conventional MMORPGs provide only a single UI for each game title, such as a Web-based UT aimed at novice users or a native UI aimed at higher-level users. However, such limitation on the UI does not allow the users with different lifestyles to easily cooperate or compete in a single game platform, which results in deterioration of long-term profitability.